1. Field of the Invention
The present invention relates generally to an air-jet type cleaner and, more particularly, is concerned with a blower tube in such a cleaner.
2. Related Background Art
An air-jet type cleaner is a kind of working machinery which jets out air from a blower tube by using a blower, so as to cause the resulting air jet flow to collect wastes such as fallen leaves at a desirable site, thereby carrying out cleaning.
Usually, when such a cleaner is used for blowing out wastes on the ground, an operator holds the base portion or proximal portion of the blower tube by hand, and tilts its front end portion or distal portion downward so as to direct the nozzle at the wastes. At this time, for efficiently blowing out wastes, it will be effective if the airflow jetted out of the nozzle of the blower tube is directed horizontally. Therefore, as shown in FIG. 1, a conventional blower tube 1 has a curved front end portion 2 in general.
When the front end portion 2 of the blower tube 1 is curved, however, it may be problematic in that the workable area is limited. For example, there are cases where the curved front end portion 2 of the blower tube 1 cannot be inserted into a narrow space between fences or walls, which makes it difficult to blow out wastes within the space.
The blower tube 1 is molded from a synthetic resin in general. When the front end portion 2 of the blower tube 1 is curved, it may be problematic in that the die for molding it becomes greater by the protrusion d of the front end portion 2, thereby raising the cost for the die.
Therefore, it is an object of the present invention to provide a blower tube for an air-jet type cleaner which can overcome the conventional problems mentioned above.
For achieving the above-mentioned object, the present invention provides a blower tube directly or indirectly connected to an air outlet of a blower in an air-jet type cleaner; the blower tube comprising a straight tube portion having one end connected to the air outlet of the blower; and a deflecting portion, extending from the other end of the straight tube portion, for receiving an airflow flowing through the straight tube portion and deflecting this received airflow away from a longitudinal axis of the straight tube portion; wherein a nozzle or an outlet for jetting out the airflow deflected by the deflecting portion is defined by the straight tube portion and deflecting portion; and wherein, with respect to a plane of projection orthogonal to the longitudinal axis of the straight tube portion, a projected image of the deflecting portion is encircled by a projected image of the straight tube portion.
In such a configuration, the deflecting part can deflect the airflow away from the longitudinal axis of the straight tube part so as to jet it out from the nozzle. Therefore, this blower tube has a function similar to that of the conventional blower tube having a curved front end portion. Further, since the deflecting part does not protrude sideways from the straight tube part in the present invention, the blower tube can be handled as if it is a straight rod-like body, whereby it can be inserted into a narrow space.
The form of the nozzle, i.e., the edge of straight tube and deflecting portions defining the nozzle, may be straight in a side-view state (see FIGS. 4 and 6). Also, in the side-view state, the edge defining the nozzle may be nonlinear and bent or curved in a direction opposite to the deflecting direction (see FIGS. 8, 10, and 12). In the latter case, the angle of emission of the airflow jetted out from the nozzle becomes wider than that in the former case. Here,xe2x80x9cside-view statexe2x80x9d refers to a state viewed along a direction perpendicular to the deflection direction of airflow caused by the deflecting portion and orthogonal to the longitudinal axis (A). In the drawings, FIGS. 4, 6, 8, 10, and 12 show the side-view state.
Preferably, the inner face of the deflecting portion is concave or planar.
Preferably, in the side-view state, the deflecting portion has a bend that reaches inward by a distance (W) which is at least ⅓ of the outer diameter (D) of the straight tube portion (See FIG. 4). This size makes it possible to reliably deflect the airflow at the flow rate of a typical airflow flowing through the blower tube, e.g., 60 to 80 m/s.